I forgot to mention that A and B are sorted (well, I sort them explicitly in my code, but I can't imagine an optimal algorithm that wouldn't require that) and that they contain a lot of entries, which are complex LOL. FWIW, A usually has ~500 entries while B usually has 20,000. In other words, a grep/map solution might be more readable, but the efficiency would likely suck. -- Peter Scott Pacific Systems Design Technologies ==== Want to unsubscribe from Fun With Perl? ==== Well, if you insist... Send mail with body "unsubscribe" to ==== fwp-request@technofile.org